1. Field of the Invention
This invention relates to a lift axle suspension mounting system and more particularly to a lift axle suspension mounting system wherein the lift axle suspension assembly is secured to the frame of a truck between the tandem axles and the cab of the truck. The lift axle may also be mounted on the rearward end of the frame rearwardly of the tandem axles. The lift axle assembly of this invention is pivotally movable with respect to the vehicle between a first position in which the wheels of the lift axle are elevated and a second position in which the wheels engage the ground. The lift axle of this invention further relates to a lift axle assembly which is designed so that a variable load may be placed upon the wheels when the wheels are in the ground engaging position. More particularly, the lift axle suspension of this invention is designed to fit truck frames having varying dimensions.
2. Description of the Related Art
Lift axle assemblies have been used for many years on work vehicles such as transit concrete mixers, gravel trucks, etc. The lift axle assemblies of the prior art permit the vehicle to carry more weight while still meeting the regulations governing the weight which the vehicles can legally carry over federal and state highways. Most of the prior art lift axle assemblies are pivotally movable with respect to the frame of the vehicle so that the wheels of the lift axle assembly may be pivotally moved from a ground engaging position to an elevated position.
Although the lift axle assemblies of the prior art have apparently met with considerable success, the prior art lift axle assemblies suffer from many shortcomings. First, the prior art lift axle assemblies are not believed to be readily adaptable to vehicle frame width variations. Additionally, the prior art lift axle assemblies are not believed to be able to adapt to vehicle frame thickness variations. Further, the maintenance and service of the prior art lift axle assemblies appears to be rather complex, in most cases. Additionally, the prior art lift axles are not believed to be able to be conveniently and easily mounted on the frames of the vehicles nor is it believed that the prior art lift assemblies are able to control lateral movement of the lift axle in a satisfactory manner.
It is therefore a principal object of the invention to provide an improved mounting system for a lift axle assembly for a vehicle such as a truck or the like.
Still another object of the invention is to provide a lift axle assembly which accommodates frame width variations and frame thickness variations.
Yet another object of the invention is to provide a lift axle suspension mounting system which is extremely safe to use.
Yet another object of the invention is to provide a lift axle suspension mounting system which is quickly and easily bolted onto the frame members of the vehicle.
These and other objects will be apparent to those skilled in the art.